Patent US3879352A successfully refreshed from Google Patents.
US3879352A
Expired / Lapsed
US
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Continuous process for polymerizing {60 ,{60 -disubstituted-{62 -propiolactones
Assignee: Eastman Kodak Co
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Filing: 1973-02-06
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Granted: 1975-04-22
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Expires: 1993-02-06
Abstract
Abstract A polymer of an Alpha , Alpha -disubstituted- Beta propiolactone may be formed by contacting the monomer of the Alpha , Alpha -disubstituted- Beta -propiolactone, a suitable polymerization initiator, and solid particles of the polymer of the Alpha , Alpha -disubstituted- Beta -propiolactone in the presence of an inert atmosphere in a suitable reactor at an elevated temperature. Polymerization of the monomer upon the walls of the polymerization reactor is inhibited by controlling the average particle size of the polymer particles by removing a portion of the polymer particles from the reactor, grinding these particles to a smaller particle size, and returning the smaller particles to the reactor.
Inventors
- 👤 William A Ames
- 👤 James J Ward
- 👤 Jr Edward H Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:19
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
95 words
IN A PROCESS FOR THE PREPARATION OF A POLYMER OF AN A,ADIALKYL-B-PRIOLACTONE WHICH PROCESS COMPRISES POLYMERIZATION OF THE SAID A,A-DIALKYL-B-PROPIOLACTONE IN CONTACT WITH A POLYMERIZATION INITIATOR AND IN THE PRESENCE OF SOLID PARTICLES OF POLYMER OF THE SAID A,A-DIALKYL-B-PROPIOLACTONE WHEREIN SAID PARTICLES ARE KEPT IN VIGOROUS MOTION IN AN INERT GASEOUS ATMOSPHERE, THE IMPROVEMENT WHICH COMPRISES CONTROLLING THE AVERAGE PARTICLE SIZE OF THE POLYMER PARTICLES WITHIN THE REACTOR BY REMOVING A PORTION OF THE POLYMER PARTICLES FROM THE REACTOR, GRINDING SAID PARTICLES TO A SMALLER PARTICLE SIZE, AND RETURNING SAID SMALLER PARTICLES TO THE REACTOR.
Claim 2
Dependent Claim
95 words
IN A PROCESS FOR THE PREPARATION OF A POLYMER OF AN A,ADIALKYL-B-PRIOLACTONE WHICH PROCESS COMPRISES POLYMERIZATION OF THE SAID A,A-DIALKYL-B-PROPIOLACTONE IN CONTACT WITH A POLYMERIZATION INITIATOR AND IN THE PRESENCE OF SOLID PARTICLES OF POLYMER OF THE SAID A,A-DIALKYL-B-PROPIOLACTONE WHEREIN SAID PARTICLES ARE KEPT IN VIGOROUS MOTION IN AN INERT GASEOUS ATMOSPHERE, THE IMPROVEMENT WHICH COMPRISES CONTROLLING THE AVERAGE PARTICLE SIZE OF THE POLYMER PARTICLES WITHIN THE REACTOR BY REMOVING A PORTION OF THE POLYMER PARTICLES FROM THE REACTOR, GRINDING SAID PARTICLES TO A SMALLER PARTICLE SIZE, AND RETURNING SAID SMALLER PARTICLES TO THE REACTOR.
Claim 3
Dependent Claim
110 words
In a process for the preparation of a polymer of an Alpha , Alpha -dialkyl- Beta -propiolactone which process comprises polymerization of the said Alpha , Alpha -dialkyl- Beta -propiolactone in contact with a polymerization initiator and in the presence of solid particles of polymer of the said Alpha , Alpha -dialkyl- Beta -propiolactone wherein said particles are kept in vigorous motion in an inert gaseous atmosphere, the improvement which comprises controlling the average particle size of the polymer particles within the reactor by removing a portion of the polymer particles from the reactor, grinding said particles to a smaller particle size, and returning said smaller particles to the reactor.
Claim 4
Dependent Claim
110 words
In a process for the preparation of a polymer of an Alpha , Alpha -dialkyl- Beta -propiolactone which process comprises polymerization of the said Alpha , Alpha -dialkyl- Beta -propiolactone in contact with a polymerization initiator and in the presence of solid particles of polymer of the said Alpha , Alpha -dialkyl- Beta -propiolactone wherein said particles are kept in vigorous motion in an inert gaseous atmosphere, the improvement which comprises controlling the average particle size of the polymer particles within the reactor by removing a portion of the polymer particles from the reactor, grinding said particles to a smaller particle size, and returning said smaller particles to the reactor.
Claim 5
Dependent Claim
20 words
The process of claim 1 wherein the polymerization is conducted at a temperature of from about 50* to about 150*C.
Claim 6
Dependent Claim
15 words
The process of claim 2 wherein the temperature is from about 70* to about 120*C.
Claim 7
Dependent Claim
28 words
The process of claim 1 wherein the amount of polymer recycled to the reactor is from about 10 to about 50 percent of the polymer in the reactor.
Claim 8
Dependent Claim
22 words
The process of claim 1 wherein the particle size of the polymer recycled to the reactor is less than about 40 mesh.
Claim 9
Dependent Claim
23 words
The process of claim 5 wherein the particle size of the recycled polymer is greater than 80 mesh and less than 40 mesh.
Claim 10
Dependent Claim
17 words
The process of claim 1 wherein the polymerization is conducted in at least two sequentially connected reactors.
Claim 11
Dependent Claim
21 words
The process of claim 7 wherein the temperature of each successive reactor is higher than the temperature in the preceding reactor.
Claim 12
Dependent Claim
108 words
In a process for the preparation of a polymer of Alpha , Alpha -dimethyl- Beta -propiolactone which process comprises polymerization of said Alpha , Alpha -dimethyl- Beta -propiolactone in contact with a polymerization initiator and in the presence of solid particles of polymer of the said Alpha , Alpha -dimethyl- Beta -propiolactone wherein said particles are kept in vigorous motion in an inert gaseous atmosphere, the improvement which comprises controlling the average particle size of the polymer particles within the reactor by removing a portion of the polymer particles from the reactor, grinding said particles to a smaller particle size, and returning said smaller particles to the reactor.
Claim 13
Dependent Claim
108 words
In a process for the preparation of a polymer of Alpha , Alpha -dimethyl- Beta -propiolactone which process comprises polymerization of said Alpha , Alpha -dimethyl- Beta -propiolactone in contact with a polymerization initiator and in the presence of solid particles of polymer of the said Alpha , Alpha -dimethyl- Beta -propiolactone wherein said particles are kept in vigorous motion in an inert gaseous atmosphere, the improvement which comprises controlling the average particle size of the polymer particles within the reactor by removing a portion of the polymer particles from the reactor, grinding said particles to a smaller particle size, and returning said smaller particles to the reactor.
Claim 14
Dependent Claim
20 words
The process of claim 9 wherein the polymerization is conducted at a temperature of from about 50* to about 150*C.
Claim 15
Dependent Claim
15 words
The process of claim 10 wherein the temperature is from about 70* to about 120*C.
Claim 16
Dependent Claim
28 words
The process of claim 9 wherein the amount of polymer recycled to the reactor is from about 10 to about 50 percent of the polymer in the reactor.
Claim 17
Dependent Claim
22 words
The process of claim 9 wherein the particle size of the polymer recycled to the reactor is less than about 40 mesh.
Claim 18
Dependent Claim
23 words
The process of claim 13 wherein the particle size of the recycled polymer is greater than 80 mesh and less than 40 mesh.
Claim 19
Dependent Claim
17 words
The process of claim 9 wherein the polymerization is conducted in at least two sequentially connected reactors.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |